Avamar: VMs that have disks set to independent disk mode are not backed up

Summary: Avamar VM Image level backups on VMs which have disks set to an independent disk-mode will not be included in a backup. This happens because no snapshots can be taken of these disks.

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Instructions

When backups are taken on a VM which has disks set to one of the independent disk modes, the data on those disks will not be included. This reason for this is that these disks are ineligible for snapshot.

To identify VMs that are configured with independent disks:

  • Edit the VM within vCenter
  • Identify the disks.
  • Expand the disk panel.
  • Identify the disk mode.

Review the following image for more details:

Edit Settings


There are several disk modes available for use:

Option Description
Dependent This is the default mode. When snapshots are taken, the disks set to dependent mode are included in the snapshot.
Independent - Persistent Disks behave like a conventional computer disk regardless of the snapshot state. Once data is written, it is permanent unless deleted from the disk.
Independent - Nonpersistent This disk mode makes the drive behave like a read-only disk. Changes made are nonpersistent and are lost once the VM is powered off, restarted, or a snapshot is consolidated. 

It is sometimes useful to set the disk mode to "Independent - Persistent". This excludes a drive from backups or prevents snapshot-related stun events.

If the VM in question needs all its attached disks to be backed up, there are two options available:

  1. Change all required disks to dependent.
  2. Use the Avamar agent to backup these snapshot-independent disks.

Additional Information

See this VMware article:
Change Disk Mode to Exclude Virtual Disks from Snapshots.
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vm_admin.doc/GUID-8B6174E6-36A8-42DA-ACF7-0DA4D8C5B084.html

 

Affected Products

Avamar Client for VMware
Article Properties
Article Number: 000211192
Article Type: How To
Last Modified: 09 Jun 2023
Version:  2
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